Rolling mill apparatus



Dec. 23, 1969 A. 1. WILSGN ROLLING MILL APPARATUS 5 Sheets-Sheet l Filed Dec." 12, 1966 w m Wm w M MW I|\l/\l E in %v W M? A v, 4 F E \w 2 s B? m 2 VII)...

Dec. 23, 1969 A. 1. WILSON 3,435,077

ROLLING MILL APPARATUS Filed Dec. 12, 1966 3 Sheets-Sheet 2 Dec. 23, 1969 A. I. WILSON 3,485,077

ROLLING MILL APPARATUS Filed Dec. 12, 1966 5 Sheets-Sheet 3 FIG .5

MvM'

United States Patent 3,485,077 ROLLING MILL APPARATUS Alexander Ian Wilson, Sheffield, England, assignor to The Hille Engineering Company Limited, Sheffield, England, a company of Great Britain and Northern Ireland Filed Dec. 12, 1966, Ser. No. 600,955

Claims priority, application Great Britain, Dec. 16, 1965,

Int. Cl. B21h 41/02 US. Cl. 72-229 3 Claims ABSTRACT OF THE DISCLOSURE In a double duo rolling mill the upper roll of one pair and the lower roll of the other pair of rolls is readily retractable from an operative position in each case defined by an abutment, to an inoperative position, material to be reduced passing to and fro through the mill and being reduced by one pair of rolls during movement in one direction and by the other pair during movement in the other direction, the widths of the roll gaps being adjustable by screw means associated with the nonretractable rolls.

The invention relates to rolling mill apparatu arranged to reduce the thickness of rods and bars during successive passes through the apparatus.

In conventional so-called double-duo arrangements, and three-high rolling mill apparatus, successive passes of material are effected in opposite directions through the apparatus, but between each pass the material generally requires to be lifted or lowered through a relatively great height to bring it into alignment with the required pass line. In addition, in the case of three-high mills, there are a number of well-known disadvantages resulting from the fact that the middle roll is common.

The main object of the invention is to provide rolling mill apparatus in which material can be reduced during successive passes and which does not suffer from the disadvantages referred to above.

According to the invention, rolling mill apparatus includes at least two pairs of co-operable rolls, a first pair being situated in advance of a second pair, and drive means connected to said pairs of rolls for driving them in contra-rotation whereby said pairs of rolls may be. used alternately for passing material in opposite directions through the apparatus, mechanism being provided for retracting to an inoperative position at least one roll of said second pair of rolls so as to allow the passage of material therethrough when said first pair of rolls is operative. Further mechanism is preferably provided for retracting to an inoperative position at least one roll of said first pair of rolls. Preferably, also, the pass line of said second pair of rolls is slightly lower than that of said first pair of rolls. A tilt table may be disposed between the two pairs of rolls and arranged to be raised at one end or the other alternately according to which pair of rolls is operable. The mechanism for retracting one or more of the rolls to an inoperative position preferably includes hydraulic rams.

In order that the invention may be fully understood and readily carried into effect, a preferred embodiment thereof will now be described, by way of example only, with reference to the accompanying drawings, of which:

FIGS. 1 and 2 are diagrammatic illustrations of one form of rolling mill apparatus embodying the invention,

FIG. 3 is a somewhat schematic end view of a practical design of mill for putting this form of the invention into effect, and

FIGS. 4 and 5 are diagrammatic illustrations of an alternative form of apparatus embodying the invention.

Referring now to FIGS. 1 and 2 of the drawings, rolling mill apparatus includes a first pair of rolls 10, 12 and a second pair of rolls 1-4, 16. The first pair of rolls are situated in advance of the second pair, and drive means (not shown) are connected to said pairs of rolls for driving them in contra-rotation as indicated by the arrows, whereby said pairs of rolls may be used alternately for passing material in opposite directions through the apparatus.

Mechanism is provided for retracting the roll 14 from the operative position in which it is shown in FIG. 2 to the inoperative position in which it is shown in FIG. 1. Further mechanism is provided for retracting the roll 12 from the operative position in which it is shown in FIG. 1 to the inoperative position in which it is shown in FIG. 2. With the rolls 12 and 14 in their operative positions, the pass line 20 through the second pair of rolls is slightly lower than the pass line 18 through the first pair of rolls.

The arrangement is such that, with the roll 14 retracted as shown in FIG. 1, a first pass of material through the apparatus from left to right can effect an initial reduction in thickness, the material passing freely between the idly rotating rolls 14, 16. The roll 14 can then be returned to its operative position whilst the roll 12 is simultaneously retracted so that a second pass of the material through the apparatus, this time from right to left, can effect a further reduction in thickness as shown in FIG. 2, the material passing freely between the idly rotating rolls 10, 12 (the material has of course been turned on edge before being passed from right to left). The slight difference in height of the pass lines enables fiat sections to be returned on edge through the apparatus from right to left, that is to say, enables 'a greater thickness of material to pass from right to left between the pairs of rolls than passed. originally from left to right regardless of the fact that the rolls 10 and 16 have not been adjusted in position between consecutive passes and the rolls 12 and 14 have not been adjusted through an excessive distance.

Referring now to FIG. 3, a practical design of mill for putting this form of the invention into effect includes a pair of roll chock housings 40 (only one of which is visible in the drawing) each having a pair of windows 42 and 44 for respective pairs of roll chocks 46, 48 and 50, 52 in which the rolls 10, 12 and 14, 16 are mounted. The chocks 46 and 52 are slidably mounted directly in guides in their respective windows whereas the chocks 48 and 50 are mounted in so-called chairs 54 and 56 which are slidably mounted in the windows.

The position of the chock 46 in each housing is determined by a screw 58 from which it depends, said screw engaging a nut 60 which is fixedly secured in the housing above the window 42. A motor 62 is provided for driving the screw upwardly or downwardly to vary the width of the roll gap between the rolls 10, 12. Similarly, the position of the chock 52 in each housing is determined by a screw 64 on which it is supported, said screw engaging a nut 66 which is fixedly secured in the housing beneath the window 44. A motor 68 is provided for driving the screw upwardly or downwardly to vary the width of the roll gap between the rolls 14, 16.

A hydraulic ram assembly 70 is provided beneath the window 42 of each housing for raising and lowering the chair 54 and thus for moving the roll 12 from the inoperative position in which it is shown in the drawing to a raised operative position. In this raised operative position of said roll, the chair 54 abuts against shoulders 72 which are formed intermediate the ends of the window. Similarly, a hydraulic ram assembly 74 is provided above the window 44 of each housing for raising and lowering the chair '56 and thus for moving the roll 14 from the.

operative position in which it is shown in the drawing to a raised inoperative position. In the lowered operative position of the roll 14 the chair 56 abuts against shoulders 76 which are formed intermediate the ends of the window 44. When either one of the retractable rolls is in its operative position, the chair in which its chocks are mounted are loaded against the shoulders against which they abut by a pressure of oil in the respective rams controlling it.

The apparatus is such that the material can quickly be returned after the initial pass and there is the minimum of wasted time. This is partly because no time is wasted in running up to speed the second pair of rolls, and partly due to the fact that the material does not require lifting or lowering through a comparatively great height between successive passes as is the case with conventional double-duo arrangements and when using a three-high mill to roll in opposite directions. In addition, apparatus embodying the invention does not suffer from the wellknown disadvantages associated with three-high mills due to their middle roll being common.

It is frequently found when using conventional doubleduo and three-high mills and due to the need to lift the material between successive low passes and high passes, that the material is not presented truly horizontally to the rolls. This is especially so when heavy sections are being rolled, and results in rolled bars which are not straight. It is thought that this tendency will be overcome by the present invention.

Referring now to FIGS. 4 and 5, in an alternative form of apparatus embodying the invention a rolling mill includes a first pair of rolls 22, 24 and a second pair of rolls 26, 28. The first pair of rolls are situated in advance of the second pair, and drive means (not shown) are connected to said pairs of rolls for driving them in contrarotation as indicated by the arrows. As in the previous arrangement, therefore, the pairs of rolls may be used alternately for passing material in opposite directions through the apparatus, mechanism including a pair of hydraulic rams as in the first described embodiment being provided for retracting the roll 26 from the operative position shown in FIG. to the inoperative position in which it is shown in FIG. 4 as required. In this case, however, the lower rolls of each pair are situated at the same height.

A tilt table generally indicated 30 is disposed midway between the two pairs of rolls and carries at its top surface a plurality of freely rotatable rollers 32 along which material can pass through the apparatus. The tilt table is mounted for tilting movement about the axis of a pivot 34 and hydraulic rams 36 and 38 are provided for effecting the required tilting movements. When the first pair of rolls are operative as in FIG. 4, the ram 38 is energized so that the tilt table guides the material clear of the surface of the roll 28. When the second pair of rolls are operative, as in FIG. 5, however, the ram 36 is energized so that the tilt table guides the material clear of the surface of the roll 24. This arrangement is primarily intended for cogging operations.

Various modifications may be made without departing from the scope of the invention. For example, the second pair of rolls could be, in effect, inverted so that the upper roll became the non-retractable roll. If the upper roll of each pair of rolls were then disposed at the same height, the tilt table might not be necessary, the

fall of the material due to gravity being relied upon to take the material clear of the idling roll. Furthermore, the pairs of rolls may be mounted in separate housings disposed closely adjacent each other instead of in common housings. Position control of the nonretractable rolls could if preferred be effected by the use of packing pieces inserted under the roll chocks. Alternately, position'coritrol could be applied to the retractable rolls by the use of packing pieces fixed upon the shoulders against which the chairs abut or upon said chairs themselves.

What I claim is:

1. Rolling mill apparatus comprising a first pair of rolls; a second pair of rolls; the respective rolls of said pairs of rolls being cooperable and counterrotatable; abutment means to define an operative position of the lower roll of the first pair and abutment means to define an operative position of the upper roll of the second pair; mechanism for retracting from their respective operative positions to their respective inoperative positions the lower roll of said first pair of rolls and the upperroll of said second pair of rolls; the first pair of rolls being situated in advance of the second pair of rolls for material to be passed through said pairs of rolls in one direction with said upper roll of said second pair in the inoperative position and said lower roll of said first pair in the operative position to efiFect an initial reduction in said first pair of rolls and subsequently to be passed through said pairs of rolls in the reverse direction with said lower roll of said first pair in the inoperative position and said upper roll of said second pair in its operative position to effect a further reduction in said second pair of rolls; and screw adjustment means associated with the respective nonretractable rolls for adjusting their respective positions upwardly and downwardly to vary the widths of the roll gaps between the pairs of rolls.

2. Rolling mill apparatus according to claim 1, wherein the second pair of rolls are so disposed in relation to the first pair of rolls that the pass line between said second pair of rolls is slightly lower than the pass line formed between said first pair of rolls.

3. Rolling mill apparatus according to claim 1, wherein the mechanisms for retracting the one roll of the second pair of rolls and the one roll of the first pair of rolls from their operative to their inoperative positions comprise respective pairs of hydraulic rams, said retractable rolls being carried in chairs which are slidably disposed in windows in roll chock housing, said chairs being loaded, by a pressure of oil in the rams controlling the positions of said retractable rolls, against shoulders formed in said windows when said rolls have been moved to their operative positions.

References Cited UNITED STATES PATENTS 605,669 6/1898 Huber 72-229 372,747 11/ 1887 Everson 72-229 387,495 8/ 1888 Daniels 72-229 898,901 9/1908 Lamberton 72-229 946,795 1/ 1910 Fawell 72-229 974,559 11/1910 Fawell 72-229 984,569 2/1911 Koch 72-234 3,331,232 7/ 1967 King 72-229 MILTON S. MEHR, Primary Examiner 

